They are about to share the screen in two new Stephen Poliakoff BBC dramas. Here, the veteran actor Michael Gambon talks David Walliams through stage fright and spear-holding

DAVID WALLIAMS I once told the actor Niall Buggy, "I love acting because I love getting to play lots of different people and sort of disguising myself." He said, " Really great actors reveal something of themselves when they act." It knocked me for six. Do you think it's concealing something about yourself or revealing something?

MICHAEL GAMBON I think it's revealing something. Every part you play, you are playing yourself, really. But you just twist yourself to reveal what's written, don't you? It's essentially you.

DW It's showing a vulnerability.

MG Yes, it's good to show vulnerability. When I was in that David Hare play Skylight, there was one bit when I just used to break down crying. It wasn't in the script, but I shoved it in because it seemed to fit the moment. Nobody, not David even, ever commented on it, so I presume they liked it. But,